What types of volcanoes are located in the ring of fire?

1 Answer
Dec 7, 2015

Arc volcanoes


These volcanoes are found above subduction zones and are the result of sediment melting from the down-going oceanic slab underneath the continental crust.

This forms magma in the mantle wedge above the slab, and the low density magma slowly rises to the surface.


These magmas are silica (#"SiO"_2#) rich and, as a result, they are very thick, much like honey.

Honey has a high viscosity and so it is thick and takes a long time to flow.

These magmas also contain a lot of water (up to 10 Wt %) and, when this water comes out of the magma, it becomes explosive and we get huge eruptions

The reason this happens is because the water prevents the magma from solidifying, and this allows gases so escape over time.

But, once the water leaves, the magma solidifies and no gas can escape.